net.freeutils.charset.Utils Maven / Gradle / Ivy
/*
* Copyright © 2005-2019 Amichai Rothman
*
* This file is part of JCharset - the Java Charset package.
*
* JCharset is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* JCharset is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with JCharset. If not, see
* This is a convenient utility method for design-time building
* of charsets based on a lookup table mapping, as an alternative
* to creating these inverse lookup tables on-the-fly.
*
* @param tables the inverse lookup (char-to-byte) table
* @return the Java definitions of the inverse lookup
* (char-to-byte) table
*/
public static String toInverseLookupTableDefinition(int[][] tables) {
StringBuilder sb = new StringBuilder();
int nulls = 0;
sb.append("static final int[][] CHAR_TO_BYTE = {\n\t");
for (int i = 0; i < tables.length; i++) {
int[] table = tables[i];
if (table == null) {
if (nulls++ % 8 == 0 && nulls > 1)
sb.append("\n\t");
sb.append("null, ");
} else {
if (nulls > 0)
sb.append("\n\t");
nulls = 0;
sb.append("{ // high byte = 0x");
if (i < 0x10)
sb.append('0');
sb.append(Integer.toHexString(i));
sb.append("\n\t");
for (int j = 0; j < table.length; j++) {
if (table[j] == -1) {
sb.append(" -1, ");
} else {
sb.append("0x");
if (table[j] < 0x10)
sb.append('0');
sb.append(Integer.toHexString(table[j])).append(", ");
}
if ((j + 1) % 8 == 0)
sb.append("\n\t");
}
sb.append("}, \n\t");
}
}
sb.append("\n\t};");
return sb.toString();
}
/**
* Main entry point for command-line utility.
*
* @param args the command line arguments
* @throws IOException if an error occurs
*/
public static void main(String[] args) throws IOException {
// parse arguments
String from = "UTF-8";
String to = "UTF-8";
List inputFiles = new ArrayList();
String outputFile = null;
PrintStream so = System.out;
try {
for (int i = 0; i < args.length; i++) {
String arg = args[i];
if (arg.startsWith("-") && arg.length() > 1 && inputFiles.isEmpty()) {
if (arg.equals("-o")) {
outputFile = args[++i]; // throws IOOBE
} else if (arg.equals("-f")) {
from = args[++i]; // throws IOOBE
} else if (arg.equals("-t")) {
to = args[++i]; // throws IOOBE
} else if (arg.equals("-l") || arg.equals("-ll")) {
String filter = arg.equals("-ll") ? Utils.class.getPackage().getName() : "";
for (Charset charset : Charset.availableCharsets().values())
if (charset.getClass().getName().startsWith(filter))
so.println(charset.name() + " " + charset.aliases());
System.exit(0);
} else if (arg.equals("-?") || arg.equals("-h")) {
so.println("Usage: java -jar jcharset.jar [options] [inputFiles...]\n");
so.println("Converts the charset encoding of one or more (concatenated) input files.");
so.println("If no files or '-' (dash) is specified, input is read from stdin.");
so.println("\nOptions:");
so.println(" -f \tthe name of the input charset [default UTF-8]");
so.println(" -t \tthe name of the output charset [default UTF-8]");
so.println(" -o \tthe output file name [default stdout]");
so.println(" -l\t\t\tlist all available charset names and aliases");
so.println(" -ll\t\t\tlist all JCharset charset names and aliases");
so.println(" -h, -?\t\tshow this help information");
System.exit(1);
} else {
throw new IndexOutOfBoundsException();
}
} else {
inputFiles.add(arg); // all remaining args are input files
}
}
} catch (IndexOutOfBoundsException ioobe) {
System.err.println("Error: invalid argument");
System.err.println("Use the -h option for help");
System.exit(2);
}
if (inputFiles.isEmpty())
inputFiles.add("-");
// perform conversion
OutputStream os = outputFile == null ? so : new FileOutputStream(outputFile);
OutputStreamWriter writer = null;
try {
char[] buf = new char[16384];
writer = new OutputStreamWriter(os, to);
for (String inputFile : inputFiles) {
InputStream is = inputFile.equals("-") ? System.in : new FileInputStream(inputFile);
try {
int count;
Reader reader = new InputStreamReader(is, from);
while ((count = reader.read(buf)) > -1)
writer.write(buf, 0, count);
} finally {
is.close();
}
}
} finally {
if (writer != null)
writer.close(); // also flushes encoder
os.close();
}
}
}